Articles
The Flint PDF library
Short, practical pieces on PDFs — fixing a typo, signing a contract, getting a file under 25 MB, picking the right format, dealing with awkward scans. 965 articles and counting.
How to share a PDF without letting people copy text
No-copy is a polite barrier. Determined exfiltration still gets through.
3 minReadHow to share a PDF without letting people edit it
Read-only PDF is straightforward to set. Worth doing for any document where edits would cause confusion.
3 minReadHow to share a PDF without letting people print it
You can discourage printing technically. Stopping it entirely needs DRM, not PDF.
4 minReadHow to tell if a PDF has been edited
PDFs leave fingerprints when they're edited. Here's where to look.
4 minReadHow to tell if a PDF is encrypted
Sometimes 'protected' just means a flag in the file. Here's how to confirm a PDF is genuinely encrypted.
3 minReadHow to track a pending PDF signature
Pending signatures need visibility, not vibes. Here's how to track and nudge.
3 minReadHow to verify a signed PDF is authentic
Don't rely on the visible signature. Verify the underlying integrity in three steps.
4 minReadHow to vet an online PDF editor for your firm
Vetting takes an afternoon and saves years of cleanup. Here's the checklist.
5 minReadIP and device info in signed PDFs
IP and user agent in a signing log are circumstantial evidence. Useful, but not infallible.
3 minReadIs a drawn signature legally valid?
Drawn signatures pass legal muster nearly everywhere. The few exceptions are narrow.
3 minReadIs a photo of a signature legally valid?
Photos of signatures are common and usually valid. The risks are about provenance, not the form itself.
4 minReadIs a typed signature legally valid?
Typed signatures are valid wherever electronic signatures are valid — which is nearly everywhere.
3 minReadIs it safe to edit PDFs online?
Some online PDF tools process in your browser. Others upload your file and keep it. Know which is which.
4 minReadIs it safe to use free PDF tools?
Free tools often mean you're the product. Some don't — here's how to tell.
4 minReadISO 27001 and your PDF tools
ISO 27001 puts the tools you use into scope. Choose vendors that simplify the audit story.
4 minReadPDF metadata redaction explained
Metadata is the invisible second leak in any PDF you share. Strip it as part of redaction.
4 minReadOwner password vs user password explained
Two passwords, two purposes. Here's which one stops people opening the file, and which one stops them editing it.
3 minReadPDF audit trails explained
The audit trail is what makes an e-signature defensible. Here's what to expect inside one.
4 minReadPDF certificate of completion, explained
The certificate is your legal receipt for a signed PDF. Here's what each field means.
4 minReadPDF encryption explained
How PDF encryption actually works — and what it doesn't protect against.
5 minReadPDF password best practices
A clear set of habits for using PDF passwords properly across a team.
4 minReadPDF password vs encryption: what's the difference?
Passwords protect access. Encryption protects content. Most people conflate them — and shouldn't.
3 minReadPDF password vs ZIP with password: which is safer?
Both work. One has fewer surprises for the recipient.
3 minReadPDF tools and data residency explained
If your data must stay in the UK, EU or specific jurisdiction, your PDF tool needs to match.
4 minReadRedaction checklist for legal filings
Litigation redaction needs procedure. Here's the checklist a careful filer runs every time.
4 minReadRedaction checklist for medical records
Medical redaction is identifier-driven. Here's the 18-point checklist Safe Harbor expects.
4 minReadRedaction for FOIA and public records requests
Redaction for FOIA isn't the same as redaction for internal sharing. The bar is higher and the audience is hostile.
5 minReadSelf-signing vs witnessed signing
Most contracts don't need a witness. The ones that do, need them done right.
3 minReadSOC 2 and your PDF tools
SOC 2 reports tell you what controls a vendor has. PDF tool choice is part of your own SOC 2 picture.
4 minReadThe most famous PDF redaction failures
When you see how it's gone wrong, you understand why proper redaction matters.
5 minReadTimestamping electronic signatures, explained
When 'when' matters, a trusted timestamp is what proves it. A short primer.
4 minReadTracked PDF views, explained
View tracking turns a PDF into a one-way audit log. Useful, with limits.
3 minReadTrue redaction vs visual redaction
If you can copy the redacted text out, it wasn't redacted. The two-second test.
3 minReadUETA, explained
The Uniform Electronic Transactions Act in plain English, with the New York exception called out.
4 minReadWhen you need a qualified electronic signature
Most contracts don't need a Qualified Electronic Signature. Here's the short list of cases that do.
4 minReadWhere do online PDF editors store your files?
The honest answer for most online PDF tools: somewhere on someone's server. Here's how to find out where.
4 minReadWhy black rectangle redaction isn't enough
Black rectangle redaction has caused some of the most famous PDF leaks. Here's how it goes wrong.
4 minReadWhy emailing PDFs isn't really secure
Email is the most common channel and the least secure. Here's why — and what to do about it.
4 minReadWhy PDF passwords aren't perfect security
A password helps. It isn't a complete answer to every threat. Here are the honest gaps.
4 minReadWhy signing then editing invalidates the signature
A signed PDF is supposed to be frozen. Editing it breaks the seal by design.
3 minRead